//==========================================================================
// Copyright (c) 2000-2008,  Elastos, Inc.  All Rights Reserved.
//==========================================================================
/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */
#include "lwip/opt.h"

#if LWIP_HAVE_LOOPIF

#include "netif/loopif.h"
#include "lwip/mem.h"

#if defined(LWIP_DEBUG) && defined(LWIP_TCPDUMP)
#include "netif/tcpdump.h"
#endif /* LWIP_DEBUG && LWIP_TCPDUMP */

#include "lwip/tcp.h"
#include "lwip/ip.h"

#include "lwip/tcpip.h"

static void
loopif_input(void * arg)
{
    struct netif *netif = (struct netif *)( ((void **)arg)[ 0 ] );
    struct pbuf *r = (struct pbuf *)( ((void **)arg)[ 1 ] );

    mem_free( arg );
    netif -> input( r, netif );
}

static err_t
loopif_output(struct netif *netif, struct pbuf *p,
    struct ip_addr *ipaddr)
{
    struct pbuf *q, *r;
    char *ptr;
    void **arg;

#if defined(LWIP_DEBUG) && defined(LWIP_TCPDUMP)
    tcpdump(p);
#endif /* LWIP_DEBUG && LWIP_TCPDUMP */

    r = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
    if (r != NULL) {
        ptr = r->payload;

        for (q = p; q != NULL; q = q->next) {
            memcpy(ptr, q->payload, q->len);
            ptr += q->len;
        }

        arg = mem_malloc( sizeof( void *[2]));
        if (NULL == arg) {
            return ERR_MEM;
        }

        arg[0] = netif;
        arg[1] = r;
        /**
     * workaround (patch #1779) to try to prevent bug #2595:
     * When connecting to "localhost" with the loopif interface,
     * tcp_output doesn't get the opportunity to finnish sending the
     * segment before tcp_process gets it, resulting in tcp_process
     * referencing pcb->unacked-> which still is NULL.
     *
     * TODO: Is there still a race condition here? Leon
     */
        sys_timeout( 1, loopif_input, arg );

        return ERR_OK;
    }
    return ERR_MEM;
}

err_t
loopif_init(struct netif *netif)
{
    netif->name[0] = 'l';
    netif->name[1] = 'o';
#if 0 /** TODO: I think this should be enabled, or not? Leon : NO, believe me, you don't want do this! wenli*/
    netif->input = loopif_input;
#endif
    netif->output = loopif_output;
    netif->flags |= NETIF_FLAG_UP;

    return ERR_OK;
}

static struct netif loopif;                                             //
void loop_init()
{
    struct ip_addr ipaddr, netmask, gw;                                 //
    IP4_ADDR(&gw, 127,0,0,1);
    IP4_ADDR(&ipaddr, 127,0,0,1);
    IP4_ADDR(&netmask, 255,0,0,0);

    netif_add(&loopif, "loopback", &ipaddr, &netmask, &gw, NULL, NULL,
            NULL, loopif_init, tcpip_input);
}

#endif /* LWIP_HAVE_LOOPIF */
